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http://dx.doi.org/10.11112/jksmi.2012.16.6.102

Assessment of Flexural Strengthening Behavior Using the Stirrup-Cutting Near Surface Mounted(CNSM) CFRP strip  

Moon, Do Young (경성대학교 토목공학과)
Oh, Hong Seob (경남과학기술대학교 토목공학과)
Zi, Goang Seup (고려대학교 토목공학과)
Publication Information
Journal of the Korea institute for structural maintenance and inspection / v.16, no.6, 2012 , pp. 102-112 More about this Journal
Abstract
Recently, the near surface mounted (NSM) FRP strengthening technique has been actively applied to deteriorated concrete structures for rehabilitation purposes. However, the use of this conventional NSM technique could be restricted due to the insufficient height or strength of the concrete cover. In this study, the stirrup-Cutting Near Surface Mounted(CNSM) technique was considered as an alternative, whereby NSM strips are placed at a deeper level, namely at the level of the main steel reinforcement. A flexural test of a concrete beam strengthened with CNSM technique was performed and the results were then compared to those for a concrete beam strengthened by the conventional NSM technique. The embedment length of the CFRP strips was varied in order to increase the effect of the anchoring depth of the NSM and CNSM CFRP strips in the beam specimens. From the results of the test, the beam with the CNSM CFRP strip showed typical structural behavior similar to that of the beam with the NSM CFRP strip. Moreover, there was no apparent structural degradation resulting from the stirrup partial-cutting. Consequently, the CNSM strengthening technique can be suitably utilized for extensively damaged concrete structures where it is difficult to apply the conventional NSM technique.
Keywords
Stirrup; CNSM; Flexural test; Rehabilitation;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
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1 ACI committee 440. 2R., Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures, American Concrete Institute, 24, 2002.
2 American Concrete Institute, Building code and commentary, ACI 318-08, Detroit, 155, 2008.
3 Barros JAO, Dias SJE, Lima JLT., Efficacy of CFRPbased techniques for the flexural and shear strengthening of concrete beams, J Cem Concr Compos, 29, 2007, 203-217.   DOI   ScienceOn
4 Barros JAO, Ferreira DRSM, Fortes AS, Dias SJE., Assessing the effectiveness of embedding CFRP laminates in the near surface for structural strengthening, Constr Build Mater, 20, 2006, 478-491.   DOI   ScienceOn
5 Bonaldo E, Barros JAO, Lourenco PB., Efficient strengthening technique to increase the flexural resistance of existing RC slabs, J Compos Constr vol. 12, No. 2, 2008, 149-159.   DOI
6 Derias M, El-Hacha R., Bond behavior of FRP in structures: state-of-the-art review, Proc., 8th Int. Symp. FRPRPs-8, Patras, Greece, 2007.
7 El-Hacha R, Filho JNS, Melo GS, Rizkalla S., Effectiveness of near surface mounted FRP reinforcement for flexural strengthening of reinforced concrete beams, Proc., 4th Int.ConfACMBS, Calgary, Canada, 2004.
8 Hassan T, Rizkalla S., Investigation of bond in concrete structures strengthened with near surface mounted carbon fiber reinforced polymer strips, J Compos Constr, vol. 7, No. 3, 2003, 248-257.   DOI   ScienceOn
9 Hassan TK, Rizkalla SH., Bond mechanism of NSM FRP bars for Flexural Strengthening of concrete structures, ACI Struct J, vol. 101, No. 6, 2004, 830-839.
10 Kang J, Park Y, Park J, You Y, Jung W., Analytical evaluation of RC beams strengthened with near surface mounted CFRP laminates, Proc., 7th Int. Symp. FRPRPs-7, Kansas City, USA, 2005, 779-794.
11 Kishi N, Mikami H, Kurihashi Y, Sawada S., Flexural behavior of RC beams reinforced with NSM AFRP rods, Proc., Int. Symp. on Bond Behavior of FRP in Structures (BBFS2005), Hong Kong, 2005, 337-342.
12 Korea Industrial Standards, The pieces for tension test for metallic materials, KS B 0801, Korea(in Korean), 1981.
13 Liu IST, Oehlers DJ, Seracino R., Tests on the ductility of reinforced concrete beams retrofitted with FRP and steel near-surface mounted plates, J Compos Constr, vol. 10, No. 2, 2006, 106-114.   DOI   ScienceOn
14 Rizkalla S, Hassan T, Hassan N., Design recommendations for the use of FRP for reinforcement and strengthening of concrete structures, Prog Struct Engng Mater, 5, 2003, 16-28.   DOI   ScienceOn
15 Seo, S., Choi. K., Kwon. Y. Retrofit Capacity of Near- Surface-Mounted RC Beam by using FRP Plate, Journal of KSMI, vol. 16, No. 1, 18-26(in Korean)
16 Seracino R, Saifulnaz MRR, Oehlers DJ., Generic debonding resistance of EB and NSM plate-to-concrete joints, J Compos Constr, vol. 11, No. 1, 2007, 62-70.   DOI   ScienceOn
17 Teng JG, De Lorenzis L, Wang B, Li R, Wong TN, Lam L., Debonding failures of RC beams strengthened with near surface mounted CFRP strips, J Compos Constr, vol. 10, No. 2, 2006, 92-105.   DOI   ScienceOn
18 Yoon J., Han J. Cho D., Park S. Crack and Debonding Donitoring of RC Beams Strengthened with CFRP Plates, Journal of KSMI, vol. 15, No. 4, 185-192(in Korean).